Cooling arrangement for flue-tube superheater elements.



. THOMSEN. comme ARRANGEMENT Foe FLUE TUBE SUPERHEATER ELEMENTS.

Patented Feb. 22,1916.

APPLICATION FILED .IULY 3l. 1915. 1,172,407.

WITNESS/5s:

PETER THOMSEN,

SCHE HEISSBAMPF-GESELLSCHAET M. B. H., OF CASSEL-WILHELMSHHE, GER- MANY, A. CORPORATION OF GERMANY.

COOLING ARRANGEMENT' FOR FLUE-T'UBE SUPERHEATER ELEMENTS.

Specification of Letters Patent. p Patented Feb, 22, 1916.

Application led July 31, 1915. Serial No. 43,048.

To all 'whom it may concern Be it known that I, PETER THoMsEN, a citizen of the German Empire, residing at Cassel-lVilhelmshhe, Germany, havev invented certain new and useful improvements in Cooling Arrangements for Flue- Tube superheater Elements, of which the following is a specification. v

My invention relates to means for cooling the superheater tubes or elements of flue tube superheaters as used i-n locomotive boilers and the like when the engine taking steam therefrom is stopped or operating under a no load condition, i. e., running free with steam supply cut off.

More particularly my invention relates to an arrangement by means of which air from the external atmosphere is automatically introduced into and circulated through the superheater elements Whenever the superheated steam supply is shut olf from the engine and whereby said flow of air through' said elements is automatically shut off when the supply of superheated steam is again turned down.

In the prior art, stationary steam installations have been provided with automatic cooling arrangements for superheater elements embodied therein, said arrangements comprising the use of openings, controlled by back pressure valves, into the saturated and superheated steam collectors, one of said openings being from thev external atmosphere and the other into the chimney or staclr. Such arrangements have not proved satisfactory for locomotives and the like, however, because the powerful suction of the engine pistons when the locomotive is running with steam cut olf has drawn a great deal of soot, smoke and dirt into the superheater and into the engine.

According to the present invention, the use of openings into the saturated and superheated steam collectors is retained, but the disadvantages of the prior art, as above referred to, are avoided by arranging the said openings at different levels, for example, by providing the opening into the superheated steam collector with a short stack or chimney opening into the atmosphere at a suitable height above the collector and at a higher level than the opening into the saturated steam collector. In this way, whenthe locomotive is stationary, there will automatically be established a partial vacuum in said stack so as to produce suction from the atmosphere through the opening into'the saturated steam collector, and when the engine is running free with steam cut 0E from the engine cylinders, the suction yof the pistons will cause air to be introduced into the superheater element through both of said openings and ejected through the eX- haust.

My invention will be better understood by referring to the accompanying drawings in which- Figure 1 shows a central longitudinal section through so much of a locomotive as is necessary for illustrative purposes, embody# ing a preferred form of my invention; and Fig. 2 shows a similar view of a modified form of the invention.

The superheater header system, o, is fixed upon the front tube sheet, a, of the boiler in the usual way and comprises saturated and superheated steam collecting chambers, c, and d, between which are connected the su perheated elements, e, disposed in flue tubes in the usual manner. The two collectors, c, and d, are connected according to the usual practice, with pipes, g, and f, which respectively take saturated steam from the steam dome and deliver superheated steam to the steam chests.

` An opening provided with a perforatedl cap, it, is made from the outside of'theen gine into the top of saturated steam collector, c, and a back pressure valve, la, which opens by its own weight when there is no steam passing through .the super-heaters, controls said opening. A'similar opening is provided in the top of the superheated steam collector, d, and leads into a tube orshort stack, m, of suitable height whose upper end is provided with a cap, n, having an over-ky hanging spaced flange for the obstruction of soot and dirt; instead of using this cap the free end vof the pipe, m, may be bent rearwardly as indicated by the dotted lines. A.' back pressure valve, o,- similar to the valve, c, controls this opening.

The operation of my invention is as follows: lVhen the engine is stationary, with main throttle closed, both back pressure Ivalves will drop, and both openings will thereby be uncovered. There will then. be established in the pipe, m, a slight upward draft and a corresponding partial vacuum in the superheated steam collector, d. This will cause a current of air to flow through the perforations of cap, h, and past the open back pressure valve, 7c, into the saturated steam collector and thence through the S11- perheater elements to the superheated steam collector and out to the atmosphere through valve o and tube m. Since the suction established by the tube, m, is relatively quite small a closing of the back pressure valve o need not be feared. If necessary the back pressure valves may be given a certain amount of spring pressure in addition to their weight. lVhen the engine is ruiming with main throttle closed (coasting) the operation of the pistons will establish a partial vacuum in the cylinders which will cause air to flow into the superheaterelements past both of the back pressure valves, k, and o. The air entering by way of valve, k, will iiow through the superheater elements and reach the superheated steam collector in heated condition from which point it will unite with the cooler air which has entered by way of pipe, m. The combined air current will then flow to the cylinders of lthe engine. As a consequence of the mixture of the two air currents, as described, the temperature of the resultant current which reaches the cylinders will be relatively low. This is desii-able in order that the cylinderl may run cool and affords a distinct advantage as contrasted with other cooling arrangements in which the entire supply of cooling air flows through the superheater.

In order to intensify Ythe suction through pipe, m, steam from the boiler may be passed therethrough. One way to accomplish this is to lead a pipe, 1", (shown dotted) from the blower connection g, the free end of pipe 1' being formed as a nozzle and projected upwardly in pipe m above the valve 0. To operate the blower independently of the branch pipe, r, or, conversely, to run steam through pipe r without operating the blower, a control valve may be placed at the point, t, where pipe, r, branches from pipe, g; this is, preferably, a multiple way cock.

lVhileI prefer the arrangement as shown in Fig. l, I may, if I choose, within the limits of my invention, connect the pipe, m, to the saturated steam chamber c and employ the perforated cap L at the opening into the superheated steam chamber, thus reversing the controls 'of the saturated and superleated steam collector openings as shown in In place of the back` pressure valves, 7c,

and, o, a manually controlled device may be i throttle in such a way that the cocks are closed when the throttle is opened and opened when the throttle is closed.

When the main throttle valve is built into or made a part of the steam collector system it may readily and conveniently be so arranged as to control the air openings into the two collecting chambers.

Having described my invention, I claim:

1. In a locomotive having flue tubes conn taining superheater elements, a saturated and a superheated steam collector between which said `elements are connected, eachl of said collectors being provided with openings into'the atmosphere at different levels and means for simultaneously opening or closin said openings according as steam is shut o i from or admitted to the superheater.

2. In a locomotive having :line tubes conn taining superheater elements, a saturated and a superheated steam collector between which said elements are connected, each of said collectors being provided with openings into the atmosphere at different levels and a back pressure valve for each openingfor opening or closing said openings according as steam is shut off from or admitted to the superheater.

3. In a locomotive having iue tubes containing superheater elements, a saturated and a superheated .steam collector between which said elements are connected, each of said collectors being provided with openings into the` atmosphere at different levels and means controlled by the main throttle for simultaneously opening or closing said openings according as steam is shut od-from or` admitted to the superheater.

l4. In a locomotive having flue tubes containing superheater elements, a saturated and a superheated steam collector between which said elements areconnected, each ofi said collectors being provided with openings into the atmosphere, the opening from the superheated steam collector having a short stack erected thereupon with its upper end opening at a higher level than is the opening from the saturated steam collector, valves controlling each lopening `and means for openingv or closing said valves simultaneously according as steam is shut olf from or admitted to the superheater.

-5. In a locomotive having flue tubes containing Superheater elements, a saturated and a superheated steam collector between which vsaid elements are connected, each of said collectors having an opening into the atmosphere, a short stack erected from the In testimony whereof Ithave hereunto set' superheated steam collector opening, a nozmy hand. 21e supplied from the blower connection opening'nto said stack7 and means for open- PETER THOMSEN' [L' 8'] ing or closing the steam collector openings Witnesses:

according as steam is shut off from or ad- CARL MOLL,

mtted to the superheater. GUsTAy RETTIG.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C. 

